Breaking the Unit Throughput Barrier in Distributed Systems

TL;DR

This paper introduces a multi-level power transmit strategy combined with random access protocols to surpass the traditional throughput limit of 1 in distributed networks, using SIR models and interference cancellation.

Contribution

It proposes a novel power level distribution approach with RAPs to achieve throughput greater than 1 in distributed systems, supported by structural analysis and simulations.

Findings

Throughput exceeding 1 is achievable with the proposed method.

Structural results facilitate finding achievable throughputs.

Simulations confirm the closeness of achievable throughput and upper bounds.

Abstract

A multi-level random power transmit strategy that is used in conjunction with a random access protocol (RAP) (e.g. ALOHA, IRSA) is proposed to fundamentally increase the throughput in a distributed communication network. A SIR model is considered, where a packet is decodable as long as its SIR is above a certain threshold. In a slot chosen for transmission by a RAP, a packet is transmitted with power level chosen according to a distribution, such that multiple packets sent by different nodes can be decoded at the receiver in a single slot, by ensuring that their SIRs are above the threshold with successive interference cancelation. Since the network is distributed this is a challenging task, and we provide structural results that aid in finding the achievable throughputs, together with upper bounds on the maximum throughput possible. The achievable throughput and the upper bounds are shown to be close with the help of comprehensive simulations. The main takeaway is that the throughput of more than 1 is possible in a distributed network, by using a judicious choice of power level distribution in conjuction with a RAP.